|
MFI |
[Ti] ZSM-5 |
Si(98.6), Ti(1.4) |
Contributed by Jan H. C. van Hooff and Arjan van der Pol
Verified by D. Serrano and by Z. Gabelica
Type Material [Ti1.3Si94.7O192] : wH2O
Method M. Taramasso, G. Perego and B. Notari [1-3]
Batch Composition TiO2: 70 SiO2:1980 H2O : 30 TPA-OH (TPA tetra-n-propylammonium)
Source Materials
distilled water
tetraethylorthosilicate [Si(OC2H5)4] (Merck 800658)
tetraethylorthotitanate [Ti(OC2H5)4] (Merck 821083)
tetrapropylammonium hydroxide (Alfa 17456, 40% solution in water)
Batch Preparation (for 43 g product)
(1) [163.3 g tetraethylorthosilicate + 2.56 g tetraethylorthotitanate], mix at 350C
(2) [(1) + 170 g tetrapropylammonium hydroxide (40% solution)], add slowly at 00C to prevent hydrolysis
(3) Heat at 800C to evaporate ethanol
(4) Add water to restore initial volume; final pH 12.2
Crystallization
Vessel: 500 mL stirred autoclave
Temperature: 1750C
Time: 2 days
Agitation: 120 rpm
Product Recovery
(1) Centrifuge to recover solids and wash with water (three times)
(2) Dry at l200C
(3) Heat in air to 5500C (heating rate 50C/min.) and hold at 5500C for 3 hours
(4) Yield 90% on SiO2
Product Characterization
XRD: orthorhombic MFI (only crystalline phase)
Elemental Analysis: 1.37 mol% Ti (72 SiO2/TiO2 by AAS) a
Crystal Size and Habit: 0.3 um cubes (SEM)
Click here to view XRD pattern
References
[1] M. Tarainasso, G. Perego, B. Notari, US Patent 4 410 501 (1983)
[2] A. J. H. P. van der Pol, J. H. C. van Hooff, Appl. Catal. 92 (1992) 93
[3] J. A. Martens, P. Buskens, P. A. Jacobs, A. van der Pol, J. van Hooff, P. J. Kooymann, H. van Bekkum, Appl. Catal. 99 (1993) 71
[4] A. Tuel, Y. Ben Taarit, Zeolites 14 (1994) 272
Note
a. No extra-framework TiO2 can be observed by IR or UV-VIS. No IR bands around 700 cm-1 and no UV-VIS bands above 250 nm were observed [4].